1. Technical Field
The present invention relates to a method for controlling medium access in a full-duplex Wi-Fi network, and more particular, to a control method for minimizing interference at an access point (AP) using a full-duplex scheme such that clients have high transfer rates.
2. Description of the Related Art
In a cellular system, a relay is used between a base station and a terminal in order to improve frequency efficiency and to expand coverage. Examples of the relay include an optical repeater and a wireless relay. Recently, research has been widely conducted on wireless relays as the wireless relays take a lower installation cost than the optical repeater and are not restricted to specific installation areas. The wireless relay receives a radio signal through a receive antenna and retransmits the same through a transmit antenna. The schemes for operation of the wireless relay are broadly divided into half-duplex and full-duplex.
A relay adopting half duplex performs transmission and reception using two orthogonal channels in the time domain or the frequency domain. Accordingly, a transmitted signal does not cause interference to a reception entity. On the other hand, a relay adopting the full-duplex scheme performs transmission or reception simultaneously. Accordingly the full duplex relay obtains high frequency efficiency, but the full-duplex deal relay is difficult to physically implement because of interference caused by a transmitted signal.
In order to implement a wireless relay adopting the full-duplex scheme, various methods for canceling interference signals have been proposed. A typical method is to cancel interference signals by processing a radio frequency signal received through a receive antenna or by converting an intermediate frequency signal into a digital signal and performing digital signal processing.
However, the conventional methods take a long time to perform processing for cancellation of interference signals, and accordingly a delay time at the relay increases. Further, when a transmit antenna is at a very long distance from a receive antenna, network installation is spatially restricted, and accordingly there is a need for a full-duplex protocol capable of excluding interference without such restriction.